Why does my broadband connection speed up and slow down?

Why does my broadband connection speed up and slow down?

Tuesday, 28 May, 2019

If your broadband speed is annoyingly inconsistent over the course of a typical day, you’re not alone.

A variety of factors can cause a slow broadband connection and correspondingly high levels of latency – the delay between a device issuing an instruction and a response being received.

Even though broadband firms are now required to advertise achievable line speeds at peak periods, performance drop-offs throughout the day can be striking.

So what causes these fluctuations, and is there anything you can do to reduce the impact slow broadband connections have on activities like gaming and media streaming?

Slow, slow, quick, quick

These are the leading causes of intermittently slow broadband connections:

  1. Domestic network traffic. A number of reports have indicated the busiest time for individual internet users is between 7pm and 9pm local time.

    Whether the rest of the world is online or asleep, local servers and connection points will be experiencing heavy traffic loads during what’s known as domestic internet rush hour.

  2. Global network traffic. We access sites from around the world, and at any given hour, a number of countries will be experiencing their internet rush hour.

    Hourly data volumes remain fairly stable across each 24-hour period. However, at midday GMT, Europeans are working, Asians are streaming and Americans are logging on.

  3. Competition among domestic devices. Much closer to home, certain devices will be gobbling up bandwidth at particular times of day.

    Consider how hard an internet connection has to work when one member of the family is streaming Netflix, another is on Skype and a third is playing Xbox Live.

  4. Wireless congestion. It’s also possible that wireless devices around the home are more active at certain periods, while interference may even originate in neighbouring homes.

    There’s more likely to be congestion on the 2.4GHz band of a broadband router than the 5GHz alternative, while changing channel on the router might also help.

  5. Hardware faults. Domestic broadband equipment is mass-produced to tight budgets, and faults may develop from loose wiring to software conflicts.

    If the issue isn’t device-specific, try replacing microfilters and beg, borrow or steal a different router temporarily. Rebooting the router may also help, as might updating its firmware.

Other tips for tackling slow broadband connections

It’s worth posting a message on your ISP’s customer forums to see if other people are experiencing similar inconsistencies, or directly contacting the ISP’s technical support teams.

Test and write down your line speed several times a day to measure performance drop-offs. This might identify possible causes, from wireless device interference to system updates.

Connecting Ethernet devices to a nearby router eliminates any WiFi-related inconsistencies. Powerline adaptors hardwire devices to the router through electrical sockets around the home.

If a connection consistently struggles at peak times, try to download media content overnight rather than streaming it live, and schedule software updates to occur while everyone’s asleep.

Neil Cumins author picture


Neil is our resident tech expert. He's written guides on loads of broadband head-scratchers and is determined to solve all your technology problems!